The possible trip comes six months after Pyongyang at the last minute canceled an invitation for Ban to visit an inter-Korean factory park in the North Korean city of Kaesong. Ban has said North Korea gave no reason for the cancellation. He had not planned to visit Pyongyang at that time.

Yonhap news agency cited an unidentified source in the U.N. when it reported Sunday about Ban's Pyongyang trip. It gave no details on the purpose of the trip or the day it would take place.

U.N. spokesman Stephane Dujarric and Seoul's Unification Ministry said they had no comment.

If the trip does take place, Ban would be the first U.N. head to visit North Korea since Boutros Boutros-Ghali in 1993.

Yonhap, quoting another unidentified U.N. source, said Ban is expected to meet Kim because it's unlikely for the secretary general to visit a U.N. member state without meeting the country's leader.

That source was quoted as saying Ban's trip could serve as a breakthrough in the standoff over North Korea's nuclear weapons program and strained ties between the two Koreas. Ban was South Korea's foreign minister before taking up the top U.N. job.

Ban had said before his canceled Kaesong park trip that he hoped his visit would help improve ties between the Koreas. Analysts in Seoul said at the time that Pyongyang may have scrapped the trip because it felt Ban would back only the views of Washington and Seoul.

International nuclear disarmament talks remain stalled since early 2009 and experts believe North Korea has since built a small and growing atomic bomb arsenal and advanced its missile program. Hundreds of thousands of combat troops from the two Koreas face each other along the world's most heavily fortified border since their war in the early 1950s ended with an armistice, and not a peace treaty.